Generally, methods for heat-treating cast components are generally known in the prior art. When cast components made of aluminum base alloys are cooled after casting, an intermetallic phase is deposited in a matrix of solid solutions rich in aluminum. In the system AlMgSi, this is an Mg2Si phase, for example, which is embedded in an α solid solution matrix. This intermetallic phase has a disadvantageous effect on the hardness of the cast component.
To enhance the material properties, what is known as solution annealing is therefore carried out, in which the cast component is heated to a temperature above the saturation line but below the eutectic temperature, at which it is held for a predetermined time. During the solution annealing, the intermetallic phase precipitated in the solid solution rich in aluminum dissolves.
To prevent the intermetallic phases from precipitating again after the solution annealing, the component is usually quenched immediately after the annealing treatment. After quenching, age-hardening may also be effected.